Lesson 1 - introduction to population

• What is a population in ecological terms?

  A group of organisms of one species living in the same place at the same time that interbreed
• What do organisms in a population compete for?

  Space, food, light, territory, and mates
• How does population size change over time?

  Numbers go up or down continuously
• What is the formula for calculating population size?

  Population = (Birth + Immigration) - (Death + Emigration)
• What causes population increase?

  Births and immigration
• What causes population decrease?

  Deaths and emigration
• What is population ecology?

  The study of how and why population sizes change over time and space
• What do ecologists try to determine in a given area?

  Population size
• What do ecologists do if population numbers change?

  They try to determine why
• Which types of populations do scientists tend to study more often?

  Keystone species, ecosystem engineers, and indicator species
• What role do elephants play in their ecosystem?

  They are considered ecosystem engineers
• What is one method for measuring populations?

  Count every individual
• What is the quadrant-count fraction method?

  A method to estimate population size by sampling a fraction of the area
• What is the mark-recapture method?

  A method used to estimate population size by capturing, marking, and recapturing individuals
• What are the three types of population dispersion?

  Clumped, uniform, and random
• What characterizes clumped population dispersion?

  Species live in large groups near required resources
• What characterizes uniform population dispersion?

  Individuals are evenly spaced, usually due to antagonistic interactions
• What characterizes random population dispersion?

  There is no specific pattern in the distribution of individuals
• What are the three life history strategies in populations?

  • Type I: Few offspring, high parental care, late loss
  • Type II: 3-6 offspring, average parental care, constant loss
  • Type III: Many offspring, low parental care, early loss
• What are the characteristics of K-selected reproductive strategies?

  • Energy into survival and reproduction
  • Fewer, larger offspring
  • Lower population growth rate
  • Thrive best in constant conditions
  • Population stays close to carrying capacity
• What are the characteristics of r-selected reproductive strategies?

  • Energy into reproduction over survival
  • Many small offspring
  • High population growth rate
  • Opportunists
  • Populations go through unstable cycles
• What type of survivorship do K-selected species tend to exhibit?

  Type I
• What type of survivorship do r-selected species tend to exhibit?

  Type III
• What is the significance of the Bubble Survivorship Lab?

  • Demonstrates concepts of survivorship
  • Allows observation of different life history strategies
  • Provides practical understanding of population dynamics